$posts= new WP_Query( array(
'post_type' => 'audio',
'order' => 'ASC',
'posts_per_page' => -1,
'meta_query' => array(
array(
'key' => 'genre',
'value' => 'pop',
)
),
));
global $wpdb;
$connections = $wpdb->get_col("SELECT meta_value FROM $wpdb->postmeta WHERE meta_key='connections'");
$formatted_conns = array(10,23,50,47);
$query = new WP_Query(array(
...
'post__not_in' => $formatted_conns,
...
));